The front end of an engine may include a plurality of drive mechanisms for driving engine components using rotational energy from a crankshaft of the engine. For example, a diesel fuel injection pump may be synchronously timed to the crankshaft to that it delivers a pulse of high pressure fuel to each fuel injector at the same timing in relation to injection timing, thereby ensuring consistent cylinder to cylinder fuel delivery amounts. In some example, to get high fuel pressures, the fuel pump may require a high drive torque to be applied. However, the inventors herein have recognized that drive torque irregularities may be high from the crankshaft and the fuel pump and the drive mechanism from the crankshaft may transmit these irregular and high levels of drive torque. This may result in friction and wear on the fuel pump, including side loading onto the diesel fuel lubricated bearings of the fuel pump.
In one example, the issues described above may be addressed by a front end of an engine comprising a first end of a crankshaft, an idler gear in meshing engagement with the first end of the crankshaft, a fuel pump drive gear in meshing engagement with the idler gear, and a fuel pump, where an input shaft of the fuel pump is directly coupled to the fuel pump drive gear. By driving the fuel pump via a series of gears, side loading of the fuel pump bearings may be reduced.
As another representation, a system for an engine may comprise a front end, comprising a first end of a crankshaft, an idler gear in meshing engagement with the first end of the crankshaft, a fuel pump drive gear in meshing engagement with the idler gear, the fuel pump drive gear having a same number of teeth as the first end of the crankshaft, a fuel pump, where an input shaft of the fuel pump is directly coupled to the fuel pump drive gear, and a back end, arranged opposite the front end, the back end including a flywheel coupled to a second end of the engine.
In yet another representation, a method for an engine may comprise driving rotation of an idler gear via a first end of a crankshaft in meshing engagement with the idler gear, the idler gear arranged at a front end of the engine, driving rotation of a fuel pump drive gear via the idler gear, the idler gear in meshing engagement with the fuel pump drive gear, and driving rotation of an input shaft of a fuel pump via rotation of the fuel pump drive gear.
In this way, by driving a fuel pump input shaft via an idler gear positioned between and in meshing engagement with a crankshaft and a gear of the fuel pump input shaft, side loading of the fuel pump bearings may be reduced. Further, frictional losses may be reduced, and the longevity of the fuel pump may be increased.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
FIGS. 1-18 are drawn to scale, though other relative dimensions may be used.